Reduced required OpenGL version to 3.0

CMakeLists.txt

 
 include_directories("${PROJECT_BINARY_DIR}")
 
-add_definitions(-DSLOP_VERSION="v6.3.42")
+add_definitions(-DSLOP_VERSION="v6.3.43")
 
 # The names have to be unique unfortunately.
 set(EXECUTABLE_NAME "slop")
                                     src/slopstates.cpp
                                     src/framebuffer.cpp
                                     src/resource.cpp
-                                    src/gl_core_3_3.c
+                                    src/gl_core_3_0.c
                                     src/shader.cpp
                                     src/window.cpp
                                     src/slop.cpp

src/framebuffer.hpp

 #ifndef N_FRAMEBUFFER_H_
 #define N_FRAMEBUFFER_H_
 
-#include "gl_core_3_3.h"
+#include "gl_core_3_0.h"
 #include <glm/glm.hpp>
 #include <GL/gl.h>
 #include <vector>

src/glrectangle.hpp

 #ifndef N_GLRECTANGLE_H_
 #define N_GLRECTANGLE_H_
 
-#include "gl_core_3_3.h"
+#include "gl_core_3_0.h"
 #include <iostream>
 #include <glm/glm.hpp>
 #include <GL/gl.h>

src/shader.hpp

 #include <string>
 #include <exception>
 
-#include "gl_core_3_3.h"
+#include "gl_core_3_0.h"
 #include <glm/glm.hpp>
 #include <glm/gtc/type_ptr.hpp>
 #include <EGL/egl.h>

src/window.hpp

 #include <exception>
 
 #include <iostream>
-#include "gl_core_3_3.h"
+#include "gl_core_3_0.h"
 #include <GL/gl.h>
 #define GL_GLEXT_PROTOTYPES
 #define GLX_GLXEXT_PROTOTYPES